If species distributions are a function of the moisture, radiation thermal and nutrient regimes then the more accurately we'track,them(ie the PERs), the better we can ' track'plant and animal response Moisture regime is only coarsely approximated by precipitation precipitation is a useful index of moisture regime at regional scales, but limited/problematic at both continental and smaller scales Problem: estimate moisture regime across entire landscape, factoring in (1)evaporation topography and soil profile how to generate gridded estimates in an analogous manner to our climate models?• If species distributions are a function of the moisture, radiation, thermal and nutrient regimes, then the more accurately we ‘track’ them (ie. the PERs), the better we can ‘track’ plant and animal response • Moisture regime is only coarsely approximated by precipitation - precipitation is a useful index of moisture regime at regional scales, but limited/problematic at both continental and smaller scales • Problem: estimate moisture regime across entire landscape, factoring in (1) evaporation (2) topography and (3) soil profile : how to generate gridded estimates in an analogous manner to our climate models?